Methods for fabricating and filling conductive vias and conductive vias so formed

ABSTRACT

Methods for forming conductive vias include forming one or more via holes in a substrate. The via holes may be formed with a single mask, with protective layers, bond pads, or other features of the substrate acting as hard masks in the event that a photomask is removed during etching processes. The via holes may be configured to facilitate adhesion of a dielectric coating that includes a low-K dielectric material to the surfaces thereof. A barrier layer may be formed over surfaces of each via hole. A base layer, which may comprise a seed material, may be formed to facilitate the subsequent, selective deposition of conductive material over the surfaces of the via hole. The resulting semiconductor devices, intermediate structures, and assemblies and electronic devices that include the semiconductor devices that result from these methods are also disclosed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to techniques for formingconductive vias of semiconductor device components and, morespecifically, to conductive via-forming techniques in which conductivematerial is selectively deposited on the surfaces of a via hole withoutbeing deposited on the major surfaces of the semiconductor devicecomponent through which the via extends. The present invention alsorelates to conductive vias with selectively deposited conductive layers,as well as to semiconductor device components that include theconductive vias and semiconductor device assemblies that include thesemiconductor device components.

2. Background of Related Art

The parallel trends of ever-decreasing size and ever-increasing abilityin the electronics industry have driven a need for semiconductordevices, semiconductor device assemblies, and semiconductor devicepackages of ever-decreasing size and ever-increasing feature density.One approach that has been taken to facilitate these trends has been tomake as many electrical connections between components as possible in agiven amount of “real estate,” or area. This approach is applicable toboth adjacent components and non-adjacent components.

Conductive vias have been used to provide electrical pathways betweencomponents that are superimposed relative to one another, but that arenot directly adjacent to each other. A conductive via, which may beformed through a circuit board, an interposer, or a semiconductordevice, provides such an electrical pathway. Conductive vias typicallyinclude a hole formed through the substrate, an insulative lining, ifthe substrate is formed from a semiconductive or conductive material,and a conductive element that passes through the opening, which may beelectrically isolated from the substrate by way of the insulativelining. As with most features of semiconductor devices, the dimensionsof the various elements of conductive vias also continue to decrease.

U.S. Pat. No. 6,841,883 to Farnworth et al. (hereinafter “Farnworth”),the entire disclosure of which is hereby incorporated herein, in itsentirety, by this reference, describes exemplary processes for formingconductive vias through semiconductor device structures. In currentstate-of-the-art processes for fabricating conductive vias, via holesare lined with materials with low dielectric constants, such as paryleneand the fluoropolymer resins (including, but not limited to,polytetrafluoroethylene (“PTFE”), fluorinated ethylenepropylene (“FEP”),ethylene-tetrafluoroethylene (“ETFE”), chlorotrifluoroethylene (“CTFE”),and perfluoroalkoxyalkane (“PFA”), which are marketed by E.I. du Pont deNemours and Company under the trademark TEFLON®). Although these andsimilar materials may be used to form very thin insulative coatings onthe surfaces of via holes, they do not adhere well to the materials(e.g., silicon) of many substrates through which via holes are formed orto the conductive materials that are subsequently introduced into thevia holes to form an electrically conductive via.

The low adhesion of such dielectric materials, as well the potential formisalignment when multiple masks are used to form and passivate viaholes may result in shorting between a conductive via and the substratethrough which the conductive via extends.

In addition, some of the processes that are currently used to fabricateconductive vias are complex, require expensive materials or equipmentthat is not widely used in semiconductor device fabrication processes,or are otherwise undesirable.

Accordingly, there are needs for processes for fabricating conductivevias with state-of-the-art dimensions and capabilities while employingcommon semiconductor device fabrication techniques.

SUMMARY OF THE INVENTION

The present invention includes a variety of aspects for fabricatingconductive vias through a substrate, as well as semiconductor devicecomponents including the conductive vias and intermediate structures.

A method for forming one or more conductive vias includes forming one ormore via holes. The via holes may extend fully or partially through asubstrate, such as a semiconductor device, an interposer, or anothersemiconductor device structure. The via holes may be formed with asingle mask, eliminating the potential for misalignment betweendifferent sections of a via hole, which are formed through layers ofdifferent materials. The via holes may be formed or subsequentlyprocessed in such a way as to facilitate adhesion of materials that aresubsequently introduced therein to the surfaces thereof. Such processingmay include providing via hole surfaces with roughened features or otherfeatures that enhance the surface areas thereof.

Alternatively, such processing may include the formation of a dielectriccoating that includes one or more films that improve adhesion of amaterial having a low dielectric constant to one or both of the materialat the surfaces of the via holes and the conductive material that willsubsequently be introduced into the via holes.

The dielectric coating may be formed in such a way as to extend onto anedge of a bond pad that is continuous with a via hole, thereby reducingthe potential for electrical shorting between a subsequently fabricatedconductive via and the material of the substrate through which theconductive via extends.

A layer or film of barrier material may also be formed over the surfacesof each via hole. By way of example only, the barrier material mayprevent interdiffusion between a conductive material and the material ofan insulative coating or of the substrate through which the via holeextends.

Conductive material may be introduced into the via hole by a variety ofprocesses. For example, a seed material coating or other “base layer”may be formed and, if necessary, patterned to remove seed material fromundesired regions of a semiconductor device structure (e.g., the majorsurfaces of the semiconductor device structure). The seed materialfacilitates selective growth of conductive material at desiredlocations, such as over the surfaces of each via hole. Thus, once theseed material coating covers only desired portions of a semiconductordevice structure, the conductive material may be selectively introducedinto the via holes and over any other desired locations of thesemiconductor device structure (e.g., on a bond pad through which a viahole extends and with which the conductive via will communicate).

Further, more complete filling of the via hole may then be accomplishedwith a filler material. If desired, the surface of the conductive viamay be made flush with one or more features of the semiconductor devicecomponent.

Once a conductive via has been formed in accordance with teachings ofthe present invention, conductive material at the blind end of the viahole and, thus, at the blind end of the conductive via, may be exposedby removing material from the backside of the substrate. Thesemiconductor device component may then be assembled with andelectrically connected to one or more other semiconductor devices in anysuitable manner.

Other features and advantages of the present invention will becomeapparent to those of ordinary skill in the art through consideration ofthe ensuing description, the accompanying drawings, and the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which depict exemplary embodiments of various aspectsof the present invention:

FIGS. 1 through 3 illustrate an example of a technique for forming a viahole partially through a substrate;

FIGS. 1, 2, and 4 depict an example of a process for forming a via holecompletely through a substrate;

FIGS. 5 and 6 depict an example of a process for passivating surfaces ofa via hole;

FIGS. 7 and 8 show fabrication of a barrier layer over surfaces of a viahole;

FIGS. 9 and 10 illustrate the formation and optional patterning of aseed material coating over surfaces of a via hole;

FIG. 11 represents selective deposition of a conductive layer oversurfaces of a via hole;

FIGS. 12 through 14 illustrate an example of a technique that employsnonselective deposition processes to form a conductive layer over thesurfaces of a via hole;

FIG. 15 is a representation of a semiconductor device structure thatincludes an electrically conductive, oxidation-resistant film over atleast a portion of a barrier layer, seed material coating, or conductivelayer that extends onto a bond pad of the semiconductor devicestructure;

FIG. 16 illustrates an exemplary process for filling a void that remainswithin a via hole with a dielectric filler material;

FIGS. 17 and 18 each show another example of a process for filling avoid that remains within a via hole with a dielectric filler material;

FIG. 19 is a depiction of a void in a via hole that has been filled witha conductive material;

FIG. 20 illustrates removal of material from the back side of asubstrate to expose conductive layers at or near a blind end of a viahole;

FIGS. 21 through 24 are cross-sectional representations showing acts inan example of a process for forming a via hole and coating, orpassivating, surfaces of the via hole with dielectric material;

FIGS. 25 through 27 illustrate examples of the deposition and patterningof a seed material coating over surfaces of a via hole;

FIGS. 28 through 34 are cross-sectional representations of anotherexample of a process for forming a via hole and coating surfaces of thevia hole with dielectric material;

FIG. 35 depicts the formation of one or more conductive layers andunderlying layers over the surfaces of the via hole shown in FIGS. 28through 34;

FIGS. 36 and 37 respectively show the formation of high surface areafeatures, such as roughness features, on the surface of a via hole toenhance adhesion of materials thereto, and the subsequent formation of adielectric layer over the high surface area surface of the via hole;

FIGS. 38 through 42 illustrate another example of a process for forminga via hole in a semiconductor device structure;

FIGS. 43 through 46 are cross-sectional representations of an example ofa process for forming a copper conductive via within a via hole;

FIG. 47 depicts introduction of a dielectric filler into a void thatremains within a via hole following fabrication of a conductive via;

FIGS. 48 and 49 show another exemplary process for fabricating a copperconductive via within a via hole;

FIGS. 50 through 53 are schematic representations that illustrate anexample of a process for fabricating a nickel conductive via within avia hole;

FIGS. 54 through 56 depict another exemplary process for forming anickel conductive via within a via hole;

FIG. 57 shows examples of processes for exposing a blind end of a blindvia hole and introducing conductive filler material into a void thatremains within a via hole following fabrication of a conductive via;

FIG. 58 is a cross-sectional representation showing a conductivestructure that is secured to a conductive via at the back side of asemiconductor device structure; and

FIG. 59 is a schematic representation of an assembly that includes asemiconductor device structure that incorporates teachings of thepresent invention.

DETAILED DESCRIPTION

A semiconductor device structure 10 according to the present inventionmay, without limitation, comprise a semiconductor device (e.g., a memorydevice, such as a dynamic random access memory (“DRAM”), static randomaccess memory (“SRAM”), Flash memory, electrically-erasable programmablememory (“EEPROM”), magnetic random access memory (“MRAM”), etc.; amicroprocessor; a microcontroller; an imaging device; or any other typeof semiconductor device), another electronic component that may befabricated by semiconductor device fabrication techniques, or asubstrate (e.g., an interposer, a circuit board, etc.).

As FIG. 1 illustrates, a semiconductor device structure 10 according tothe present invention includes a substrate 12 with an active surface 14and a back side 13 opposite from active surface 14. Substrate 12 maycomprise a full or partial wafer of semiconductor material (e.g.silicon, gallium arsenide, indium phosphide, etc.), asemiconductor-on-insulator (“SOI”) type substrate (e.g.,silicon-on-glass (“SOG”), silicon-on-sapphire (“SOS”),silicon-on-ceramic (“SOC”), etc.), or even a dielectric (e.g., glass,sapphire, ceramic, polymer, resin, etc.) or metal substrate.

Semiconductor device structure 10 may be processed to form one or moreconductive vias that extend partially into or completely throughsubstrate 12. Processes of the present invention may be effected at the“wafer level” or “wafer scale,” prior to separation of adjacentcomponents from one another, as described in Farnworth.

With reference to FIG. 2, in forming via holes 20 (FIG. 3) throughsubstrate 12, a mask 40 may be formed over a surface (e.g., activesurface 14) of substrate 12. Mask 40 may be formed by known processes.For example, a photoresist may be disposed on active surface 14 ofsubstrate 12, selectively exposed through a reticle, then developed,baked, or otherwise processed, as known in the art, to form a photoresist mask, or “photomask.”

Apertures 42 of mask 40 are positioned so as to facilitate materialremoval from portions of one or more upper bond pads 15 that are carriedby active surface 14 of substrate 12 and, thus, the formation of viaholes 20 (FIG. 3) through upper bond pads 15. Apertures 42 may beconfigured so as to form via holes 20 with desired cross-sectionalshapes (e.g., circular, square, etc.).

As shown in FIG. 3, via holes 20 may be formed through upper bond pads15 and into substrate 12 by exposing the portions (e.g., center portions15 c) of upper bond pads 15 and substrate 12 that are exposed throughapertures 42 to one or more etchants suitable for removing the materialof upper bond pads 15, substrate 12, and any intervening materiallayers. While the etchant or etchants that are used to form via holes 20may be isotropic (i.e., etch in all directions at substantially the samerate) or anisotropic (i.e., not isotropic), anisotropic etchants areparticularly useful for forming via holes 20 with high aspect ratios(i.e., height-to-width, or cross-sectional dimension ratios). Materialmay be removed from substrate 12 through apertures 42 of mask 40 untilvia holes 20 of desired depth have been formed. Alternatively, knownlaser drilling processes may be used, with or without a mask, to formvia holes 20 in substrate 12.

A single mask 40 may be used in the process shown in FIG. 3. Forexample, a first etchant may be used to remove material of upper bondpads 15 through apertures 42. A second etchant or solvent may be used toremove material (e.g., borophosphosilicate glass (BPSG), a polymer,etc.) of one or more protective layers 17 that laterally surround andmay underlie upper bond pad 15 through apertures 42, prior to thecomplete removal of mask 40. As mask 40 may be partially orsubstantially removed while upper bond pads 15 and protective layer 17are etched, protective layer 17 and the remaining portions of upper bondpads 15 may then serve as a mask through which material (e.g., silicon)of substrate 12 is removed. Of course, the etchant or etchants that areused to remove material of substrate 12 are selective for the materialof substrate 12 over the materials of upper bond pads 15 and protectivelayer 17 (i.e., the etchant removes the material of substrate 12 at afaster rate than the materials of upper bond pads 15 and protectivelayer 17). The use of a single mask 40 prevents misalignment of thesections of a via hole 20 that extend through different materials.

The resulting via holes 20 may comprise blind via holes, as illustrated,which do not extend fully through substrate 12 and, thus, include blindends 22. Blind via holes 20 facilitate vacuum handling of semiconductordevice structure 10 or a fabrication substrate (not shown) by whichsemiconductor device structure 10 is carried during fabrication ofconductive vias through semiconductor device structure 10.

Alternatively, as depicted in FIG. 4, open via holes 20′, which extendcompletely through substrate 12, may be formed by removing the materialof substrate 12 through apertures 42 of mask 40.

If a photomask was used as mask 40 to facilitate material removal fromselected locations of upper bond pads 15, substrate 12, and any othermaterial layers or features of semiconductor device structure 10, thephotomask may be removed once the material removal processes have beencompleted.

Surface 24 or surfaces of each via hole 20, 20′ may be sufficientlyrough to facilitate adhesion of materials thereto. Such roughness may beachieved through the material removal process by which via holes 20, 20′are formed, or by subsequent processing. For example, without limitingthe scope of the present invention, via holes 20, 20′ may be formed by atetramethylammonium hydroxide (“TMAH”) wet etch (e.g., 9:1 H₂:TMAH), awet etch with NH₄F (ammonium fluoride), H₂O₂ (peroxide), and C₆H₈O₇(citric acid) (e.g., 1:1:1 NH₄F:H₂O₂:C₆H₈O₇), with an SF₆ plasma etch,by a deep silicon reactive ion etch (“RIE”), or the like. Alternatively,via holes 20, 20′ that have been formed by other processes may beroughened by use of a suitable roughening technique, such as one of thejust-described etch techniques.

With reference to FIG. 5, if substrate 12 is formed from a semiconductormaterial or a conductive material, surfaces 24 of via holes 20 may belined or coated with dielectric material to form a dielectric coating28, which prevents electrical shorting as electrical currents areconveyed along circuitry that extends into or through via holes 20. Thethickness of dielectric coating 28 may be tailored to position asubsequently formed conductive via at a desired location relative to asurface 24 or blind end 22 of via hole 20.

As a nonlimiting examples dielectric coating 28 may include a parylene,a low-silane oxide (“LSO”) (which is deposited by chemical vapordeposition (“CVD”) at a relatively low temperature), a material layer(e.g., an aluminum-rich oxide, etc.) that has been deposited by pulseddeposition processes and, thus, is referred to as a pulsed depositionlayer (“PDL”), or any combination of dielectric materials or layers maybe applied to or deposited onto exposed surfaces of substrate 12 byknown processes (e.g., spin coating, spraying, programmed materialconsolidation processes (e.g., those effected by the systems availablefrom Objet Geometries, Ltd., of Rehovot, Israel, 3D Systems Corporationof Valencia, Calif., etc.), CVD, thermal growth, spin-on dielectric(“SOD”) techniques (e.g., spin-on glass (“SOG” processes), etc.).Examples of processes for forming dielectric layers are disclosed inU.S. Pat. Nos. 6,770,923 and 6,541,280, as well as in U.S. PatentPublication Nos. US2005/0006768, US2002/0137317, and US2002/0137250, thedisclosures of each of which are hereby incorporated herein, in theirentireties, by this reference.

If desired, portions of dielectric coating 28, for example, portionsthat cover upper bond pads 15 or other locations of active surface 14,may be subsequently removed. Suitable techniques for selectivelyremoving various regions of dielectric coating 28 include, but are notlimited to, dry etch processes and wet etch processes. For example,spacer etch techniques, in which the etch process is effected at a lowpressure that imparts ions with a direction energy that removes materialfrom horizontal surfaces without substantially removing it from verticalsurfaces, may be used to selectively remove portions or, or pattern,dielectric coating 28. Such processes may be timed or an end pointdetected to prevent undesired removal of materials from within via holes20 (e.g., from surfaces 24). Other techniques for selectively removingregions of dielectric coating 28 may be effected with or without a mask(e.g., a photomask, which may be sprayed on, for example, by sonicdispense processes), which substantially fills via holes 20 and throughwhich upper bond pads 15 are exposed, with active surface 14 eithershielded by or exposed through the mask. When a mask is used, wet ordry, isotropic or anisotropic etch processes may be used to patterndielectric coating 28. Of course, once dielectric coating 28 has beenpatterned, the mask may be removed (e.g., by known resist striptechniques). As another alternative, planarization or polishingprocesses, such as chemical mechanical planarization (“CMP”) may be usedto remove dielectric coating 28 from active surface 14 and surfaces ofupper bond pads 15.

In forming a dielectric coating 28 on surface 24 of via hole 20, surface24 of via hole 20 may first be coated with a first adhesion layer 25comprising an oxide, such as a silicon oxide. The oxide of firstadhesion layer 25 may be formed by any suitable process, including bydeposition using tetraethylorthosilicate (“TEOS”), thermal growthprocesses, or low-temperature oxidation processes. First adhesion layer25, if present, may facilitate adhesion of a material having an evenlower dielectric constant (“K”) over surface 24 of via hole 20.

A dielectric material having a relatively low dielectric constant (e.g.,K≈2) may be deposited directly onto surface 24 of each via hole 20 oronto adhesion layer 25 that coats at least portions of surface 24. Ofcourse, the processes that are used to form dielectric layers 26 arecompatible with the material or materials from which dielectric layers26 are to be formed, as well as the materials or structures over whichthe dielectric material is to be formed or deposited. Examples of low-Kdielectric materials that may be deposited over surface 24 include, butare not limited to, parylenes (e.g., PARYLENE HT®), TEFLON®, and otherdielectric materials with low dielectric constants that may be depositedon features (e.g., within via holes 20) with relatively high aspectratios to form relatively thin dielectric layers 26.

An optional, second adhesion layer 27 may be formed over dielectriclayer 26 to facilitate adhesion of conductive materials over the surface24 of each via hole 20. Like first adhesion layer 25, second adhesionlayer 27 may comprise an oxide, such as a silicon oxide. Any suitableprocess may be used to form adhesion layer 27, including, withoutlimitation, deposition of the material of second adhesion layer 27(e.g., with TEOS when second adhesion layer 27 comprises a siliconoxide).

Portions of first adhesion layer 25 (if present), dielectric layer 26,and second adhesion layer 27 (if present) that overlie each upper bondpad 15 may be removed therefrom to facilitate communication betweensubsequently formed conductive structures and upper bond pad 15. Theremoval of the dielectric materials of these layers 25, 26, or 27 may beeffected simultaneously/sequentially, as shown in FIG. 6, or immediatelyfollowing the formation of each sequential layer 25, 26, or 27.

Layers 25, 26, 27 may be referred to hereinafter, individually or in anycombination, as “dielectric coating 28.”

Referring now to FIG. 7, a barrier layer 29 may be formed overdielectric coating 28. Barrier layer 29 is particularly useful forpreventing undesirable reactions between copper conductors within viaholes 20 and the exposed material of dielectric coating 28 or substrate12. Suitable materials from which barrier layer 29 may be formedinclude, without limitation, titanium (Ti), titanium nitride (TiN),tantalum (Ta), tantalum nitride (TaN), and other materials that preventinterdiffusion and spiking between copper and silicon andsilicon-containing materials.

As illustrated, barrier layer 29 may be formed by so-called “blanket”deposition processes, in which upper exposed surfaces (e.g., activesurface 14, surfaces exposed within via hole 20, etc.) of semiconductordevice structure 10 are coated with the material of barrier layer 29. Tofacilitate the subsequent, selective deposition of conductive material,for example, on upper bond pads 15 and surfaces 29 s of barrier layer29, as depicted in FIG. 8, the material of barrier layer 29 may beremoved from locations of semiconductor device structure 10 or substrate12 thereof (e.g., active surface 14) where deposition of conductivematerial could be problematic (e.g., cause electrical shorting) or isotherwise not desired. The removal of unwanted barrier material may beeffected by a variety of known processes, including, but not limited to,spacer etching, polishing or planarization techniques (e.g., mechanicalpolishing, chemical mechanical polishing (“CMP”), etc.), or otherwise,as known in the art.

Surfaces 24, 28 s, 29 s of via holes 20, dielectric coating 28, orbarrier layer 29, respectively, may be at least partially coated with aseed material, which will facilitate subsequent growth of a desiredconductive material on surfaces 24, 28 s, or 29 s, as shown in FIG. 9.Of course, the seed material of the resulting coating 30 facilitatesgrowth or deposition of one or more desired types of conductivematerials over surfaces 24, 28 s, or 29 s. For example, when surface 24,28 s, or 29 s is to be lined with copper, the seed material coating 30may itself comprise copper. A copper seed material coating may be formedby any suitable deposition technique, such as a physical vapordeposition (“PVD”) process (e.g., sputtering) or a CVD process. Asanother example, any suitable process (e.g., PVD, CVD, etc.) may be usedto form an aluminum film on surface 24, 28 s or 29 s.

When blanket deposition techniques are used to form coating 30, the seedmaterial may cover all of the exposed surfaces of semiconductor devicestructure 10, including areas where subsequent deposition of conductivematerial is not desired (e.g., areas other than upper bond pads 15 andsurface 24, 28 s, 29 s). Accordingly, as illustrated in FIG. 10,portions of seed material coating 30 may be removed from these areas.Any suitable technique may be used for this purpose, including, withoutlimitation, known polishing or planarization techniques.

When via holes 20 are to be filled with copper, as an alternative toseparately removing barrier layer 29 and seed material coating 30 fromsome of the surfaces of semiconductor device structure 10, as shown inFIGS. 8 and 10, a single removal process may be used to remove both seedmaterial coating 30 and barrier layer 29. This single removal processmay comprise any process suitable for removing barrier material and seedmaterial from undesired locations on the exposed surface or surfaces ofsemiconductor device structure 10, while leaving barrier material andseed material at locations where subsequent growth or deposition ofconductive material is desired (e.g., on upper bond pads 15, on surfaces24, 28 s, 29 s (FIG. 9) within via holes 20, etc.). Exemplary removalprocesses include, but are not limited to, known spacer etch techniques,polishing or planarization techniques, and the like.

Once seed material coating 30 has been formed and patterned, conductivematerial (e.g., a metal, conductor-filled polymer, etc.) may beselectively deposited on or otherwise applied to a surface 30 s thereofto form a conductive layer 32 over surfaces 24 of via holes 20 and,optionally, over upper bond pads 15 or portions thereof, as shown inFIGS. 11 through 14. By way of nonlimiting example, known electrolessplating, immersion plating, or electrolytic plating techniques may beused. Conductive material may be deposited until conductive layer 32reaches a desired thickness, in which case a void 34 (FIGS. 11 and 14)may remain within via hole 20, or until via hole 20 is completelyfilled; i.e., no void remains within via hole 20.

FIG. 11 illustrates selective deposition of a conductive layer 32 onseed material coating 30. For example, copper may be selectivelydeposited (e.g., by electroless or immersion plating; e.g., with thechemistry available from Pac Tech GmbH of Nauen, Germany) onto a seedmaterial coating 30 that also comprises copper. Alternatively, aconductive layer 32 comprising nickel may be selectively deposited(e.g., by electroless or immersion plating; e.g., with the chemistryavailable from Pac Tech) on a seed material coating 30 that comprisesaluminum.

As an alternative to selective techniques for depositing conductivematerial to form conductive layers 32 over surfaces 24 of via holes 20,nonselective deposition processes may be employed. An exemplary methodfor forming conductive layers 32′ by nonselective deposition processesis shown in FIGS. 12 through 14.

In FIG. 12, a mask 40′ is formed over active surface 14 by knownprocesses. For example, and not to limit the scope of the presentinvention, mask 40′ may comprise a photomask that is formed by applyinga photoresist over active surface 14, selectively exposing thephotoresist, developing the photoresist, removing undevelopedphotoresist, then baking the photoresist. Mask 40′ includes apertures42′ that are aligned over via holes 20 that have been formed withinsubstrate 12, lined with one or more dielectric material layers orcoatings (e.g., dielectric coating 28 or sublayers thereof, including,without limitation, adhesion layers 25 and 27 and dielectric layer 26(see FIGS. 5 and 6)), optionally coated with a barrier layer 29, andoptionally including a seed material coating 30. Apertures 42′ need notexpose entire upper bond pads 15, as upper bond pads 15 may include amaterial or materials that facilitate adhesion of a desired materialthereto.

As mask 40′ will physically separate portions of a subsequently formedconductive layer 32′, as shown (FIG. 13), from portions of each of theaforementioned layers that overlie non-upper bond pad 15-bearing regionsof active surface 14 of substrate 12, portions of seed material coating30, the optional barrier layer (not shown), and dielectric coating 28that overlie non-upper bond pad 15-bearing regions of active surface 14need not be removed prior to the formation of conductive layer 32′.

Conductive layer 32′ may be formed by any suitable process, including,but not limited to, PVD, CVD, electrolytic plating, electroless plating,and immersion plating techniques. Such a deposition or plating processmay be used to form conductive layer 32′ on surfaces of seed materialcoating 30 that are exposed through aperture 42′ of mask 40′ and, whenthe deposition process is not selective, on exposed surfaces of mask40′. By way of nonlimiting example, a conductive layer 32′ comprisingnickel may be formed on a seed material coating 30 that comprisescopper. The nickel may be deposited onto mask 40′ and portions of seedmaterial coating 30 that are exposed through aperture 42′ by anysuitable process, such as an electrolytic, electroless, or immersionplating process.

Thereafter, as depicted in FIG. 14, mask 40′ may be removed by suitableprocesses. Continuing with the example of a photomask, any suitablemask-strip process may be employed. As mask 40′ (FIG. 13) is removedfrom semiconductor device structure 10′, any portions of conductivelayer 32′ that previously overlied mask 40′ are “lifted off” ofsemiconductor device structure 10′.

If undesired portions of seed material coating 30, or barrier layer 29were not previously removed from exposed surfaces of semiconductordevice structure 10′ (e.g., from non-upper bond pad 15-bearing regionsof active surface 14), suitable processes may be used to remove one ormore of these layers or coatings following the removal of mask 40′. Inaddition to the aforementioned techniques for removing these layers orcoatings, removal processes (e.g. use of wet or dry etchants inappropriate processes) with selectivity for the materials of the layersor coatings over the material of conductive layer 32′ may be employed.

Optionally, as depicted in FIG. 15, if any of conductive layer 32, seedmaterial coating 30, or barrier layer 29 extends onto upper bond pads 15and the material of conductive layer 32, seed material coating 30, orbarrier layer 29 forms an oxide, which is not compatible with processesfor subsequently securing conductive elements (e.g., bond wires, solderballs, leads, conductive elements of tape-automated bonding (“TAB”)substrates, etc.) to upper bond pads 15, an electrically conductive,oxidation resistant coating 39 may be formed on conductive layer 32,seed material coating 30, or barrier layer 29. Oxidation resistantcoating 39 may, for example, comprise aluminum, gold, platinum, or anyother oxidation resistant material that is compatible with the materialof conductive layer 32. Oxidation resistant coating 39 may be formed bya selective (e.g., electroless or immersion plating) or non-selective(e.g., CVD, PVD, etc.) deposition process. If a non-selective depositionprocess is used, oxidation resistant coating 39 may be patterned byknown processes (e.g., use of mask and etch processes, mask and lift-offprocesses, etc.).

With reference to FIG. 16, if, following the formation of conductivelayer 32, 32′, a void 34 remains within via hole 20, a filler material35 may be introduced into void 34. Filler material 35 may comprise aconductive material, such as the same type of material use to formconductive layer 32, 32′ (e.g., a metal) or a material that iscompatible with the material of conductive layer 32, 32′ (e.g., anothermetal, a metal alloy, a conductive polymer, conductor-filled polymer,etc.), or a dielectric material (e.g., a polymer). Filler material 35 ina liquid state (e.g., molten metal, heated thermoplastic polymer,uncured polymer, etc.) may be introduced into void 34 by any suitableprocess. For example, a known “backfilling” process, in which fillermaterial 35 is mechanically forced into void 34, may be used.Alternatively, if a vent (not shown) has been formed between blind end22 of via hole 20 and a back side 13 of substrate 12, filler material 35may be drawn into void 34 by capillary action or under a negativepressure (e.g., a vacuum), or forced into void 34 under positivepressure.

While a bump 37′ may be formed by a dielectric filler material 35, asshown in FIG. 17, such a bump 37′ may prevent a conductive structurefrom being secured to and establishing adequate electrical communicationwith upper bond pad 15. Accordingly, as illustrated in FIG. 18,dielectric bumps 37′ may be removed from over surfaces of upper bond pad15 and, thus, dielectric filler material 35 may have an upper surface 35s that is flush, or substantially coplanar, with the surface 15 s ofeach upper bond pad 15.

Alternatively, as depicted in FIG. 19, a conductive via 38 may becompleted by filling void 34 with a conductive material. In theillustrated example, a conductive filler 36 (e.g., a solder, such astin/lead (Pb/Sn) solder, a so-called “lead-free solder,” such as acopper/tin/silver (Cu/Sn/Ag), tin/copper (Sn/Cu), tin/silver (Sn/Ag), orgold/tin (Au/Sn) alloy), or other suitable conductive material) may beintroduced into void 34 to fill the same and, optionally, to form a bump37 on upper bond pad 15.

As yet another alternative, voids 34 may remain within the conductivevia 38, avoiding the stresses (e.g., mismatched coefficients of thermalexpansion, mismatched electrical conductivities or resistivities, etc.)that may be caused by introducing dielectric or conductive materialtherein.

As illustrated in FIG. 20, blind ends 22 (FIG. 19) of via holes 20 and,thus, of conductive vias 38 may be exposed through back side 13 ofsubstrate 12 by removing material from back side 13 of substrate 12. Ofcourse, any suitable technique may be used to expose blind ends 22. Forexample, a so-called “back grinding” process may be used to removematerial from a back side 13 of substrate 12 until a bottom portion 33of conductive layer 32, which is located at blind ends 22 (see FIGS. 16and 19), is exposed, as illustrated, or until a partial or full crosssection of the various layers of conductive via 38 is exposed. Theexposed bottom portion 33 of conductive layer 32 of each conductive via38 forms a bottom bond pad 16 of semiconductor device structure 10.

Back side 13 may be subsequently processed to passivate the same, toform larger bond pads at the bottom ends of conductive vias 38, as wellas to form conductive traces that extend laterally to other bond padlocations, and other features, as desired.

The following EXAMPLES describe various examples of processes that maybe used to form various embodiments of conductive vias that extend intoor through semiconductor device components.

Example 1

With reference to FIGS. 21 through 27, an example of a process that maybe used to form via holes 20 in a substrate 12 and insulate, orpassivate, surfaces 24 thereof is described.

In FIG. 21, a via hole 20 is formed in substrate 12. While via hole 20is depicted as extending only partially through substrate 12 and is,thus, known in the art as a “blind via hole,” via hole 20 mayalternatively extend completely through substrate 12. Via hole 20 may beformed by any suitable process, including, without limitation, by use ofa mask through which one or more etchants selectively remove material ofsubstrate 12, by laser ablation techniques, or otherwise, as known inthe art.

While FIGS. 21 through 27 depict the process of EXAMPLE 1 as beinguseful for forming conductive vias that extend through “blind” areas ofsubstrate 12, which do not include integrated circuitry or bond pads,these processes may also be used to form conductive vias that extendthrough bond pads that are located over either blind or active areas ofsubstrate 12.

As shown in FIG. 22, a first adhesion layer 25 is formed on surface 24of via hole 20 and on an active surface 14 of substrate 12. Adhesionlayer 25 may be formed by any suitable process, such as a depositionprocess (e.g., pulsed layer deposition (“PLD”) (which forms a PDL), CVD,atomic layer deposition (“ALD”), a process for forming an LSO, etc.), asa thermal oxide, by a low-temperature oxidation process, such as thatdisclosed in U.S. Pat. No. 6,165,808, issued to Zhang on Dec. 26, 2000,the disclosure of which is hereby incorporated by this reference as isset forth in its entirety herein, or otherwise, as known in the art.

Known processes are then used to deposit a layer 26 comprising low-Kdielectric material, such as parylene, TEFLON®, or the like over firstadhesion layer 25, as depicted in FIG. 23. Due to the low-K of thematerial or materials from which dielectric layer 26 is formed, it maybe relatively thin, facilitating the fabrication of via holes 20 withrelatively large aspect ratios and, thus, increasing the potentialdensity of conductive vias that may be included on substrate 12 per agiven area over active surface 14 or back side 13 thereof.

As the material from which dielectric layer 26 is formed may not adherewell to many conductive materials, another, second adhesion layer 27,formed from a material that will adhere to both the material ofdielectric layer 26 and a subsequently deposited material, may be formedover dielectric layer 26, as shown in FIG. 24. Second adhesion layer 27comprises a dielectric material (e.g., a silicon oxide) and may beformed by known processes, such as suitable PLD or LSO techniques.

Next, as shown in FIG. 25, a conductive layer, which may also bereferred to as “seed material coating 30” or as a “metal mask,” isformed over second adhesion layer 27. In this EXAMPLE 1, seed materialcoating 30 is formed by depositing tungsten over second adhesion layer27. Tungsten is useful for facilitating the subsequent formation ofnickel over surface 24 of via hole 20.

Portions of seed material coating 30 that overlie active surface 14 ofsubstrate 12 are removed, as illustrated in FIG. 26. These portions maybe removed by any suitable process, including the use of so-called“spacer etch” techniques, which will not remove significant portions ofseed material coating 30 located within via hole 20.

Thereafter, as depicted in FIG. 27, exposed portions of second adhesionlayer 27 (i.e., those overlying active surface 14 of substrate 12) areremoved. Again, any suitable removal processes may be used, such as aselective wet etch (i.e., the etchant has selectivity for the materialof second adhesion layer 27 over seed material coating 30). Thus, seedmaterial coating 30 acts as a “metal mask” that prevents removal ofportions of second adhesion layer 27 that overlie surface 24 of via hole20 while exposed portions of second adhesion layer 27 are removed.

Portions of dielectric layer 26 that overlie active surface 14 ofsubstrate 12 may also be removed. Again, any suitable process may beused to remove material of dielectric layer 26. For example, whendielectric layer 26 is formed from parylene or TEFLON, a known,so-called “plasma strip,” process may be employed.

Once desired portions of dielectric layer 26 have been removed, portionsof first adhesion layer 25 that overlie active surface 14 of substrate12 may be removed. Any suitable processes may be used to remove theseportions of first adhesion layer 25, including, but not limited to, theuse of wet etchants, including wet etchants that will remove material offirst adhesion layer 25 with selectivity over the material or materialsthat are present at active surface 14 of substrate 12.

Example 2

FIGS. 28 through 35 illustrate another example of a process that may beused to form via holes 20 in a substrate 12 and insulate, or passivate,surfaces 24 of via holes 20.

In FIG. 28, a via hole 20 is formed in substrate 12.

As shown in FIG. 29, a first adhesion layer 25 is formed on surface 24of via hole 20 and on an active surface 14 of substrate 12. Portions offirst adhesion layer 25 that overlie active surface 14 of substrate 12are then immediately removed, as shown in FIG. 30.

Next, as illustrated in FIG. 31, a layer 26 comprising low-K dielectricmaterial is deposited over remaining portions of first adhesion layer 25and over active surface 14. Thereafter, portions of dielectric layer 26that overlie active surface 14 are removed, as depicted in FIG. 32.

A second adhesion layer 27 is then formed, as shown in FIG. 33. Portionsof second adhesion layer 27 that overlie active surface 14 aresubsequently removed, while portions of second adhesion layer 27 thatare adjacent to dielectric layer 26 remain, as shown in FIG. 34.

Thereafter, as shown in FIG. 35, a conductive layer 32 and anyunderlying layers may be formed. Thereafter, any voids 34 remainingwithin via hole 20 may be filled, as described above in reference toFIGS. 16 through 19.

While FIGS. 28 through 35 depict the process of EXAMPLE 2 as beinguseful for forming conductive vias that extend through “blind” areas ofsubstrate 12, which do not include integrated circuitry or bond pads,these processes may also be used to form conductive vias that extendthrough bond pads that are located over either blind or active areas ofsubstrate 12.

Example 3

In another exemplary via hole formation and insulation technique, whichbuilds upon the process flow described in EXAMPLES 1 and 2, the firstadhesion layer may be omitted and replaced with a process for rougheningsurface 24 of via hole 20, as shown in FIG. 36. Surface 24 may beroughened, for example, by the process or processes that are used toform via hole 20. Alternatively, a separate etch process may be used toincrease the roughness of surface 24. The roughness of surface 24enhances the direct adhesion of dielectric layer 26 or dielectriccoating 28 to the material of substrate 12 at surface 24, as shown inFIG. 37.

Example 4

FIGS. 38 though 42 illustrate the formation of a via hole 20 (FIG. 42)through an upper bond pad 15 carried by substrate 12. When mask and etchtechniques are employed to form via hole 20, a series of etch processesmay be used. This is because the material of upper bond pad 15 differsfrom the material of underlying portions of a dielectric protectivelayer 17 and the material of substrate 12, over which protective layer17 lies, and different etchants may be needed to remove these materials.

In FIG. 39, a mask 40 is formed over active surface 14 of substrate 12.Any suitable masking process may be used, including the formation of aphotomask over active surface 14. An aperture 42 of mask 40 ispositioned so as to facilitate material removal from a portion of upperbond pad 15. Aperture 42 may be located so that material may be removedfrom the center of upper bond pad 15, or so that material removal willbe effected from a location that is offset from the center of upper bondpad 15.

As shown in FIG. 40, material of upper bond pad 15 is removed. Theremoval of material of upper bond pad 15 may be effected with a singleetch or, if necessary to remove multiple conductive layers, a pluralityof etches. The removal process may be either isotropic or anisotropic,either wet or dry.

Once a portion of protective layer 17 that underlies upper bond pad 15is exposed through upper bond pad 15, a material removal process that issuitable for removing the material of protective layer 17 is effected,as FIG. 41 illustrates. This protective layer 17-removal process may beisotropic or anisotropic, wet or dry.

If necessary, another mask 40″, such as a photomask, may be formed overactive surface 14 to prevent the removal of material of protective layer17 during subsequent processing, as illustrated in FIG. 42.

Portions of substrate 12 that are exposed through the opening 20′ inupper bond pad 15 and protective layer 17, and through an aperture 42″of mask 40″, may be exposed to an etchant to extend opening 20′ intosubstrate 12 and, thus, to form a via hole 20 therein. While the etchantmay be an isotropic etchant or an anisotropic etchant, a wet etchant ora dry etchant, it is notable that the use of an anisotropic etchant maymaximize the aspect ratio of the resulting via hole 20.

Once via hole 20 has been formed, any resist remaining on substrate 12may be removed therefrom, as known in the art (e.g., by use of suitableresist strip processing). The surface areas of surfaces 24 of each viahole 20 may be increased, as explained in EXAMPLE 3, and a dielectriccoating 28 (not shown in FIGS. 38 through 42) may be fabricated oversurfaces 24 of each via hole 20, as described in EXAMPLES 1 and 2.

Alternatively, via hole 20 may be formed by other known processes (e.g.,laser ablation).

EXAMPLES 5 through 8 describe various techniques and process flows forforming conductive layers within via holes 20.

Example 5

Referring now to FIGS. 43 through 47, an exemplary process for formingconductive vias that comprise copper conductive elements is described.

Once a via hole 20 has been formed, surfaces 24 thereof may be coatedwith one or more layers of dielectric material, as illustrated in FIG.43, to form a dielectric coating 28 over surfaces 24. Processes such asthose disclosed in EXAMPLES 1 through 3 may be used to coat surfaces 24of via holes 20 with dielectric material, as may any other suitabletechniques.

A copper barrier layer 29″ (e.g., Ta, TaN, Ti, TiN, etc.) (e.g., about150 Å thick) may then be formed, as depicted in FIG. 44. Copper barrierlayer 29″ overlies dielectric coating 28 and prevents undesirableinterdiffusion between a subsequently formed copper conductive elementand the material or materials of dielectric coating 28 or substrate 12.Examples of materials that may be used to form copper barrier layer 29″include, without limitation, titanium nitride, tantalum nitride,tantalum, and the like. These and other materials that act as a barrierbetween copper and silicon-containing materials may be deposited byknown processes (e.g., CVD).

Portions of copper barrier layer 29″ that overlie active surface 14 ofsubstrate 12 are then removed. Known processes may be used to removethese portions of copper barrier layer 29″, including, but not limitedto, spacer etch processes and mask and etch processes. Followingremoval, and depending at least in part upon the type of removal processemployed, portions of copper barrier layer 29″ remain within via hole 20and, optionally, over upper bond pad 15.

In FIG. 45, a seed material coating 30″ of copper (e.g., about 2,000 Åthick) is formed on upper bond pads 15, over active surface 14 ofsubstrate 12, and on portions of copper barrier layer 29″ that remainwithin via holes 20. The copper of seed material coating 30″ may bedeposited by known processes, including CVD and PVD processes.

When blanket deposition processes are used to deposit the copper of seedmaterial coating 30″, portions of seed material coating 30″ that overlieactive surface 14 of substrate 12 are removed to prevent electricalshorting across active surface 14 (e.g., at locations between conductivevias or between a conductive via and a bond pad or other electricallyconductive structures that are exposed to active surface 14). Theseportions of seed material coating 30″ may be removed by any suitableprocess, including by known planarization or polishing processes (e.g.,mechanical polishing, chemical-mechanical polishing, etc.), with aspacer etch or otherwise, as known in the art.

Next, as shown in FIG. 46, a conductive layer 32″ (e.g., about 1 μmthick), which comprises copper, is formed over remaining portions ofseed material coating 30″. Conductive layer 32″ may be formedselectively on seed material coating 30″, without covering other regionsof substrate 12 or features carried thereby. For example, knownelectroless plating, immersion plating, or electrolytic platingtechnologies, such as the chemistries available from Pac Tech, may beused to selectively deposit the copper of conductive layer 32″.

Example 6

The process flow of EXAMPLE 5 may be modified somewhat, as shown inFIGS. 48 and 49. In FIG. 48, barrier layer 29′″ remains completelyintact as a seed material coating 30′″ is formed thereover. Once seedmaterial coating 30′″ is formed, regions of both seed material coating30′″ and barrier layer 29′″ that are not located within via hole 20 orover upper bond pad 15 are removed, as shown in FIG. 49. These portionsof seed material coating 30′″ and barrier layer 29′″ may be removed byany suitable process or processes including, but not limited to, use ofa polishing technique (e.g., CMP), a spacer etch, or the like.

Example 7

Turning now to FIGS. 50 through 53, an exemplary embodiment for forminga nickel conductive element in a via hole 20 is described.

FIG. 50 shows a substrate 12 with an upper bond pad 15 carried by activesurface 14 thereof. A nickel film 15′ is plated onto upper bond pad 15by known techniques, such as electroless, immersion, or electrolyticplating techniques. A via hole 20 is then formed through upper bond pad15 and in substrate 12, by a suitable process, such as that described inEXAMPLES 1 through 4.

Thereafter, as shown in FIG. 51, a dielectric coating 28″″ is formedover surfaces 24 of via hole 20, on nickel film 15′, and on activesurface 14 of substrate 12. Dielectric coating 28″″ may include onelayer (e.g., an oxide film formed by PLD or LSO) or more (e.g., adielectric layer formed from a non-silicon-containing low-K material andone or more optional adhesion layers, as described in EXAMPLES 1 and 2).Notably, dielectric coating 28″″ need not be etched or otherwiseselectively removed prior to the subsequent deposition process.Optionally, a barrier layer 29 (not shown) may be formed over dielectriccoating 28″″.

A seed material coating 30″″ is then formed over dielectric coating28″″. Seed material coating 30″″, which may comprise copper, is formedon dielectric coating 28″″ by known processes, such as by CVD or PVDtechniques. A mask 40″″, such as a photomask, may then be formed overseed material coating 30″″. Mask 40″″ includes an aperture 42″″positioned relative to each via hole 20 so as to facilitate theintroduction of material into via hole 20, but prevent the exposure ofportions of seed material coating 30″″ that overlie remaining portionsof upper bond pad 15 and active surface 14 to such material.

As FIG. 52 illustrates, following the formation of mask 40″″, nickel isplated onto portions of seed material coating 30″″ that are exposedthrough each aperture 42″″ to form a conductive layer 32″″ (e.g., havinga thickness of about 3 μm to about 5 μm) thereover. Nickel plating maybe effected by any suitable process, including, but not limited to,electroless plating techniques, immersion plating techniques, andelectrolytic plating techniques. As illustrated, mask 40″″ limits theextent of conductive layer 32″″. Once conductive layer 32″″ has beenformed, mask 40″″ may be removed by techniques that are known in theart. Any nickel remaining on mask 40″″ is lifted off as mask 40″″ isremoved.

Conductive layer 32″″ may then serve as a mask for the removal ofexposed portions of seed material coating 30″″ and, once these portionsof seed material coating 30″″ are removed, for the removal of thesubsequently exposed portions of dielectric coating 28″″, as shown inFIG. 53. Such removal may be effected by use of one or more etchantsthat remove the copper or other material of seed material coating 30″″or the material or materials of dielectric coating 28″″ with selectivityover the nickel of conductive layer 32″″.

Example 8

Another technique for forming a nickel conductive element of aconductive via is described with reference to FIGS. 54 through 56.

After a via hole 20 has been formed in active surface 14 of substrate 12(e.g., through an upper bond pad 15 carried by active surface 14, asdepicted), and a dielectric coating 28 has been formed over surfaces 24of via hole 20 (e.g., by the process described in EXAMPLES 1 and 2), abase layer comprising an aluminum film 30′″″ is formed over activesurface 14, upper bond pad 15, and dielectric coating 28, as shown inFIG. 54. The use of aluminum is desirable because of its low electricalresistivity and the ease with which aluminum films may be formed andpatterned. Aluminum film 30′″″ may be formed by known processes,including, without limitation, use of CVD and PVD techniques. Theseprocesses may be used to uniformly and conformally coat aluminum overexposed regions of upper bond pad 15 and over surfaces 24 of relativelydeep (i.e., high aspect ratio) via holes 20.

When blanket deposition processes are used to form aluminum film 30′″″,portions of the aluminum film 30″″′ that are located over active surface14 of substrate 12 (e.g., on protective layer 17, as depicted), areremoved, as FIG. 55 depicts. Such removal may be effected by suitabletechniques; for example, with spacer etch or polishing processes.

With reference to FIG. 56, remaining portions of aluminum film 30′″″ maybe coated with nickel. The nickel forms a conductive layer 32′″″ overaluminum film 30′″″. While any suitable nickel-deposition process may beemployed to form conductive layer 32′″″, if conductive layer 32′″″ isformed by a selective deposition process, such as an electroless,immersion, or electrolytic plating process, the resulting conductivelayer 32′″″ will only coat exposed portions of seed material coating30′″″ and remaining portions of upper bond pad 15 and subsequentmaterial removal processes will not be needed. In addition, when suchprocessing is used, nickel may be applied to both upper bond pad 15 andover surface 24 of via hole 20 simultaneously, rather than separately.

As conductive layer 32′″″ may extend over upper bond pad 15, it is notnecessary to plate upper bond pad 15 with nickel or any other conductivematerial prior to the formation of conductive layer 32′″″.

Example 9

Conductive features (e.g., portions of seed material coating 30′″″,conductive layer 32′″″, conductive filler 36 (e.g., a solder, such astin/lead (Pb/Sn) solder, a so-called “lead-free solder,” such as acopper/tin/silver (Cu/Sn/Ag), tin/copper (Sn/Cu), tin/silver (Sn/Ag), orgold/tin (Au/Sn) alloy), or other suitable conductive material), etc.)within each via hole 20 form a conductive via 38 through substrate 12.When these features are exposed to a back side 13 of substrate 12, theyform a bottom bond pad 16 at back side 13 of substrate 12, asillustrated by FIG. 57.

When blind via holes 20 are formed and filled, blind end 22 of each viahole 20 may be exposed through a back side 13 of substrate 12 by anysuitable process. For example, known back-grinding techniques or etchingprocesses may be used to remove material from back side 13 and exposevia hole 20 or structures therein to back side 13.

Example 10

With continued reference to FIG. 57, a void 34 (FIG. 56) that remainswithin a via hole 20 may be filled with conductive filler 36, such as amolten metal or metal alloy (e.g., solder). Conductive filler 36 may beapplied to a surface 13, 14 of substrate 12 by any suitable process(e.g., in a bath, in a wave solder apparatus, etc.), and permitted tofill voids 34. Conductive filler 36 may, for example, be drawn into void34 by capillary action. Alternatively, conductive filler 36 may beforced into via holes 20 under negative pressure, positive pressure, ormechanical force.

As shown, a conductive bump 37 may remain on upper bond pad 15.Alternatively, or in addition, a conductive bump could protrude relativeto back side 13 of substrate 12. If desired, conductive bump 37 may beremoved by known processes (e.g., by suitable etching processes).

Example 11

Alternatively, as shown in FIG. 47, any void 34 (FIG. 46) that remainswithin a via hole 20 may be filled with a plug of an electricallynonconductive, or dielectric, filler material 35. By way of nonlimitingexample, a liquid (e.g., molten, uncured, etc.) dielectric fillermaterial 35 may be applied to active surface 14 of substrate 12 by anysuitable technique (e.g., spin-on processes, spraying, etc.) and may bepassively or actively (e.g., under pressure or force) introduced intovoid 34 to at least partially fill the same.

If necessary or desired, excess dielectric filler material 35 may beremoved (e.g., with a suitable solvent or etchant) from one or bothsurfaces 13, 14 of substrate 12, as well as any features (e.g., upperbond pads 15) thereon.

Example 12

Turning now to FIG. 58, electrical communication may be established withconductive vias 38 and, thus, with their corresponding upper bond pads15 and circuitry (e.g., in the case where semiconductor device structure10 is a semiconductor device, with integrated circuitry of thesemiconductor device) that communicates with upper bond pads 15, bysecuring external conductive elements 50 to bottom bond pads 16.External conductive elements 50 may, by way of example only, comprisethe illustrated balls or bumps of conductive material (e.g., metal, ametal alloy such as a solder, a conductive polymer, a conductor-filledpolymer, etc.), conductive pins, pillars, or columns, or a so-calledz-axis conductive film, which includes a dielectric film with conductivefilaments extending only along the thickness, or z-axis, thereof.

External conductive elements 50 may be used to electrically connectsemiconductor device structure 10 to another electronic component. Forexample, as shown in FIG. 59, contacts (e.g., bottom bond pads 16) ofsemiconductor device structure 100 may be aligned with correspondingcontacts 112 of another semiconductor device component 110, then thecontacts (e.g., bottom bond pads 16) and their corresponding contacts112 secured to one another, in electrical communication, with externalconductive elements 50. The presence of separate contacts (e.g., upperbond pads 15) on the opposite surface of semiconductor device structure100 facilitates the disposition, or “stacking,” of another electroniccomponent, such as the depicted semiconductor device component 120, oversemiconductor device structure 100, with contacts 122 of the uppersemiconductor device component 120 being aligned with and secured inelectrical communication (e.g., with conductive bump 37) tocorresponding contacts (e.g., upper bond pads 15) of the middlesemiconductor device structure 100.

Other examples of assemblies in which semiconductor device structures100 according to the present invention may be used are described inFarnworth, as are electronic devices within which semiconductor devicestructure 100 may be incorporated.

Although the foregoing description contains many specifics, these shouldnot be construed as limiting the scope of the present invention, butmerely as providing illustrations of some of the presently preferredembodiments. Similarly, other embodiments of the invention may bedevised that do not depart from the spirit or scope of the presentinvention. Features from different embodiments may be employed incombination. The scope of the invention is, therefore, indicated andlimited only by the appended claims and their legal equivalents, ratherthan by the foregoing description. All additions, deletions andmodifications to the invention as disclosed herein, which fall withinthe meaning and scope of the claims, are to be embraced thereby.

1. A method for forming a conductive via of a semiconductor devicecomponent, comprising: forming a via hole; increasing an area of atleast one surface within the via hole without substantially increasing alength and a width of the via hole; forming a base layer comprising analuminum film on surfaces of a substrate of a semiconductor devicestructure, including over at least one surface of the via hole extendingat least partially through the semiconductor device structure; removingmaterial of the base layer from some surfaces of the semiconductordevice structure, with material of the base layer remaining on the atleast one surface of the via hole; and selectively depositing conductivematerial onto portions of the base layer remaining following the act ofremoving material to form the conductive via.
 2. The method of claim 1,further comprising: forming a dielectric coating over the at least onesurface of the via hole.
 3. The method of claim 2, wherein forming thedielectric coating comprises: forming an adhesion layer on the at leastone surface; forming a dielectric layer on the adhesion layer; andforming another adhesion layer on the dielectric layer.
 4. The method ofclaim 3, wherein each of forming the adhesion layer and forming theanother adhesion layer comprises forming a layer comprising an oxide. 5.The method of claim 3, wherein forming the dielectric layer comprisesforming a dielectric layer comprising a low-K dielectric material. 6.The method of claim 2, wherein forming the dielectric coating comprisesforming the dielectric coating to extend onto an edge of a bond pad thatis continuous with the via hole.
 7. The method of claim 6, whereinremoving material of the base layer comprises leaving material of thebase layer on at least a portion of a surface of the bond pad.
 8. Themethod of claim 1, wherein forming the base layer comprises forming aseed material coating.
 9. The method of claim 8, wherein forming theseed material coating comprises forming a seed material coatingcomprising copper.
 10. The method of claim 9, further comprising:forming a barrier layer prior to forming the base layer.
 11. The methodof claim 10, wherein forming the barrier layer comprises forming a layercomprising at least one of titanium, titanium nitride, tantalum, andtantalum nitride.
 12. The method of claim 9, wherein selectivelydepositing conductive material comprises selectively depositing copper.13. The method of claim 12, wherein selectively depositing coppercomprises electroless plating, immersion plating, or electrolyticplating.
 14. The method of claim 1, wherein selectively depositingconductive material comprises selectively depositing nickel over thealuminum film.
 15. The method of claim 1, further comprising: afterselectively depositing conductive material onto portions of the baselayer, filling a void remaining within the conductive via with a fillermaterial.
 16. The method of claim 15, further comprising: exposing theconductive via through a back side of the substrate.
 17. The method ofclaim 15, wherein filling a void comprises filling the void with adielectric filler material.
 18. The method of claim 17, furthercomprising: making a surface of the dielectric filler materialsubstantially flush with a surface of an adjacent structure or featureat a surface of the semiconductor device structure.
 19. The method ofclaim 15, wherein filling a void comprises filling the void with aconductive material.
 20. The method of claim 19, wherein filling thevoid includes forming a conductive bump that protrudes from a surface ofthe semiconductor device structure.
 21. A method for forming a via holein a substrate, comprising: forming a mask including at least oneaperture over the substrate, with the at least one aperture aligned overa portion of a bond pad carried by the substrate; removing material ofan exposed portion of the bond pad through the at least one aperture toform an opening through the bond pad; removing one or more materials ofthe substrate beneath the bond pad through the opening; and increasingan area of at least one surface within the via hole after removing theone or more materials of the substrate beneath the bond pad through theopening without substantially increasing a length and a width of the viahole.
 22. The method of claim 21, wherein removing material of anexposed portion of the bond pad is effected with an etchant that willremove the one or more materials without substantially removing materialof the bond pad.
 23. A method for forming a conductive via of asemiconductor device component, comprising: forming a via hole in asemiconductor device structure; increasing an area of at least onesurface within the via hole without substantially increasing a lengthand a width of the via hole; forming a base layer comprising an aluminummaterial on the at least one surface of the via hole; and selectivelydepositing conductive material onto portions of the base layer.
 24. Themethod of claim 23, wherein forming the base layer includes forming thebase layer on other surfaces of the semiconductor device structure. 25.The method of claim 24, further comprising: removing material of thebase layer from the other surfaces of the semiconductor devicestructure, with material of the base layer remaining on the at least onesurface of the via hole.
 26. The method of claim 23, wherein selectivelydepositing conductive material comprises selectively depositing theconductive material onto portions of the base layer remaining followingthe act of removing material to form the conductive via.
 27. A methodfor forming a conductive via of a semiconductor device component,comprising: forming a via hole; increasing an area of at least onesurface within the via hole without substantially increasing a length ofthe via hole; forming a base layer comprising an aluminum film onsurfaces of a substrate of a semiconductor device structure, includingover at least one surface of the via hole extending at least partiallythrough the semiconductor device structure; removing material of thebase layer from some surfaces of the semiconductor device structure,with material of the base layer remaining on the at least one surface ofthe via hole; and selectively depositing conductive material ontoportions of the base layer remaining following the act of removingmaterial to form the conductive via.
 28. The method of claim 27, whereinselectively depositing conductive material comprises selectivelydepositing nickel over the aluminum film.
 29. A method for forming aconductive via of a semiconductor device component, comprising: forminga via hole; increasing an area of at least one surface within the viahole without substantially increasing a length of the via hole; forminga base layer comprising conductive material on surfaces of a substrateof a semiconductor device structure, including over at least one surfaceof the via hole extending at least partially through the semiconductordevice structure; removing material of the base layer from some surfacesof the semiconductor device structure, with material of the base layerremaining on the at least one surface of the via hole; selectivelydepositing conductive material onto portions of the base layer remainingfollowing the act of removing material to form the conductive via; andfilling a void remaining within the conductive via with a dielectricfiller material.
 30. The method of claim 29, further comprising making asurface of the dielectric filler material substantially flush with asurface of an adjacent structure or feature at a surface of thesemiconductor device structure.